1. Field of the Invention
This invention relates to a method and apparatus for the manufacture of filter plugs for use in cigarettes and like articles.
More particularly, this invention relates to a method and apparatus for the manufacture of such filter plugs from a web of material, such as cellulose acetate, with particulate material deposited on said web and gathered with said web to form the filter plug.
Specifically, the invention relates to a method and apparatus for the handling of tow to provide for a channel of web material into which particulate material can be deposited at spaced positions axially thereof to accurately control the location of the particulate material in each filter plug ultimately cut from the formed filter rod.
2. Description of the Prior Art
Throughout the last decade, the tobacco industry has focused considerable attention on providing high quality filtering components having a zone, region or part thereof comprised of loose particulate or granular material. Typically, this material lies between sections of filtering material such as cellulose acetate, or paper, which have been gathered into a conventional plug form with the particulate material circumferentially bounded by a plug wrapper.
In other instances it has been deemed desirable to position the particulate material within or throughout other filtering material such as cellulose acetate. In regard to the latter, particulate material is typically provided at spaced positions along a web of filter material such as cellulose acetate and the web and particulate material are then gathered into a filter rod by garniture assemblies.
Numerous difficulties, however, have developed in attempting to place particulate material accurately on a web being fed through a high speed filter forming machine and in maintaining the particulate material in a desired position as it is being gathered into a filter rod.
If the particulate material within a filter plug is to achieve its desired end, that of filtering the smoke, the smoke must flow through the minute spaces between the particles of the material so that the surfaces of the particles are exposed to the smoke. Moreover, it is critical that a reasonable degree of consistency be provided as the filtering capability of the cigarettes so that the taste and pressure drop does not vary widely among cigarettes of the same brand.
Accordingly, it is a primary object of this invention to provide a new and improved method and apparatus for forming filters containing particulate material which will alleviate the aforementioned difficulties in the art.
It is also a primary object of this invention to provide such a new and improved method and apparatus that may be utilized commercially in relation to high speed cigarette making operations in an inexpensive and efficient manner.
A further object of this invention is to provide such a method and apparatus which will produce a high quality filter plug having the desired characteristics for properly filtering the smoke and being of a shape and character that is acceptable to provide a high quality smoking article.
It is another object of this invention to provide such a method and apparatus wherein the ultimate disposition of the particulate material within the filter plug can be accurately controlled to provide consistency of filtering and smoking characteristics.
It is also an object of this invention to provide a method and apparatus which minimizes the loss of particulate material during processing, thus minimizing housekeeping problems.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.